Detroit Lions running back
Best hasn't played in a game since Week 6 of the 2011 season after suffering what was his second concussion of that season in a loss to 49ers.
Best is in Baltimore for tonight's Ed Block Courage Awards Foundation banquet as the Lions representative.
"It's tough. I don't know what the future is going to hold for me," Best told the Baltimore Sun. "It's been about a year and a half now, but I'm still working out like I'm playing next week. ... I am never giving up hope. I'm staying ready so if the opportunity does present itself, I'll be ready."
Detroit Lions general manager Martin Mayhew said one of his biggest regrets from a disappointing 4-12 season in 2012 was not having a backup plan in place for Best when he never got his clearance to return to contact.
Not wanting to make the same mistake twice, Mayhew went out and signed veteran
Back in November, when Best was named the recipient of the Lions' Ed Block Courage Award, he told Detroitlions.com that he wasn't giving up hope of a return to football.
"It's disappointing, but I'm a glass-half-full kind of guy," he said. "To me it's just a minor setback and I'm still working and still staying ready because when I do get my chance I'm going to be ready.
"They said I couldn't play (the 2012) season, but they didn't close the door (on 2013). It doesn't matter how long it takes me, as long as my body is fresh, then I'm going to stay ready to play. If they give me a chance, and they say it's safe for me to play, then I'll be out there."
"I'm doing everything I can to get back."